“接触者追踪”
用英语怎么说？

In early January 2020, Robert Redfield, the director of the CDC, contacted George Fu Gao, the head of China’s CDC, after learning about an unidentified respiratory virus in Wuhan. At the time, Chinese authorities assured the world that there was no evidence of human-to-human transmission. They believed the cases originated from animals in a wet market. However, Redfield argued that family clusters made this animal-only theory unlikely. He offered to send an American team to investigate, but his request was denied. A few days later, Gao admitted they were too late. The virus had already spread silently beyond Wuhan. Experts later realized that the virus was highly infectious and spread mostly through asymptomatic carriers. This made standard contact tracing and isolation extremely difficult, as half of the cases showed no symptoms. This initial misjudgment set the stage for a global catastrophe.

2020年1月初，美国疾控中心（CDC）主任罗伯特·雷德菲尔德在得知武汉出现一种不明呼吸道病毒后，联系了中国疾控中心主任高福。当时，中国官方向世界保证，没有证据表明该病毒会人传人。他们认为这些病例源于华南海鲜市场的动物。然而，雷德菲尔德指出，家庭聚集性病例使这种仅限动物传播的理论显得不太可能。他提出派遣美国团队协助调查，但这一请求未获批准。几天后，高福承认他们已经太迟了。病毒早已在武汉以外悄然传播。专家们后来意识到，该病毒具有高度传染性，且主要通过无症状感染者传播。这使得标准的接触者追踪和隔离工作变得极其困难，因为有一半的病例没有表现出任何症状。这一初期误判为全球性灾难埋下了伏笔。